Side-seam-sealed container

ABSTRACT

A container for packaging fluids is made from a scored folded blank of coated paperboard. The container is made resistant to leakage by preventing the uncoated edge of a side-sealing panel from taking up fluid. This edge is protected by skiving a strip adjacent to the edge of the sealing panel, scoring the center of the skived strip and folding it on the scoring so that the skived faces are in intimate contact with each other. The container is folded from the prepared blank and seam sealed.

Unite States Patent Henry J. Haas Scarsdale, N.Y.;

Leon W. La Bombard, Nashua, N11. 862,098

June 25, 1969 V Division of Ser. No. 628, 709, Apr. 5, 1967, Pat. No.3,495,507.

Sept. 14, 1971 International Paper Company New York, NY.

lnventors Appl. No. Filed Patented Assignee SlDE-SEAM-SEALED CONTAINER 4Claims, 6 Drawing Figs.

11.8. CI 229/37 R, 229/17 G, 229/3. 1, 229/48 T Int. Cl 865d 5/40 Fieldof Search 229/37, 3.1,

[56] References Cited UNITED STATES PATENTS 2,333,330 11/1943 Moore229/48 X 2,959,336 11/1960 Mosse et a1. 229/48 X 3,365,111 1/1968McNair, lr.et a1. 229/17G 3,444,792 5/1969 Thesing et a1 93/35 PrimaryExaminer-Donald F. Norton Attorney-Charles B. Smith ABSTRACT: Acontainer for packaging fluids is made from a scored folded blank ofcoated paperboard. The container is made resistant to leakage bypreventing the uncoated edge of a side-sealing panel from taking upfluid. This edge is protected by skiving a strip adjacent to the edge ofthe sealing panel, scoring the center of the skived strip and folding iton the scoring so that the skived faces are in intimate contact witheach other. The container is folded from the prepared blank and seamsealed.

HEAT AD PRESSURE BQND PATENIED SEPMIBII F'IGJ FIG.6.

Q m I m m m m m d m {MM 0 lo m U by n mwm w mm Xx vi I 4 a m r 3 w HM 7m WW" mm w ma w H 5% a a; w 3? 0 w d w W" n u w e 5 4 M M M. u N n B H nH g N I If 7 u i E n .3 I 7'" n a R m; u l m if" I I w u l 1 M a? m HSIDE-SEAM-SEALED CONTAINER This is a division of application Ser. No.628,709, filed Apr. 5, 1967, now U.S. Pat. No. 3,495,507.

BACKGROUND OF INVENTION The packaging in paperboard containers of fluidssuch as soft drink syrups raises problems of leakage both into and outof the container. The containers are made of coated paperboard, scoredand folded to the desired shape. The blanks for the containers are cutfrom the paperboard and thus have unsealed edges. If the fifth" orsealing panel is on the inside, the contained fluid wicks into the rawedge weakening the container so that it may rupture under stress. If thesealing panel is on the outside, unwanted foreign material may leak intothe container by wicking.

Efforts have been made in the past to inhibit and hopefully to stop thisleakage with mixed results. The uncoated edges have been coated withsealing material. The coating on one face and the paperboard have beenremoved in a strip and the remaining coating folded over. The edgeportions of the container material have been skived and folded togetherwith intervening adhesive. Feather-edge or tapered skiving has also beenused.

SUMMARY OF INVENTION Containers of the kind contemplated are made forblanks of paperboard coated with a substantially impervious layer orfilm of a plastic material such as polyethylene or another plastichaving suitable qualities. Many containers of this kind are ofrectangular section, usually square. For making such a container theblank is scored to define four sidewall panels and a relatively narrowside-sealing panel sometimes called the fifth" panel. The blank isfurther scored to divide each panel into top, body, and bottom or endsections.

In order to better solve the noted problems of making coated paperboardcontainers, it is proposed in accordance with this invention to preparethe container blank for assembly by skiving a strip on the sealing orfifth panel to a depth equal to half the thickness of the blank. A lineis then scored down the middle of this strip on its unskived facedividing it into two parallel, half-width strips. The skived portion isthen folded on the scored line so that the skived faces are in contact.Since the skived portion of the strip is half-thickness and the stripportions flanking the scored line are equal in width, the edge of thestrip when folded fits tightly against the edge of the ledge formed byskiving and the folded portion is of the same thickness as the mainstock. Because of the scoring and of the snug fit, no adhesive is neededin the fold. However, it is important that the fold line be ironed toreduce the springback tendency and thus keep the fold from unfoldingthrough the heat activation period.

The side seam panel, which is bounded on its inner edge by a scored linebetween it and the adjacent body panel, is folded on this line to fitagainst a mating panel. The direction of the folding is such that thefolded-over portion of the skived strip makes contact with the matingpanel. Thus if the fifth panel is on the inside the folding is in onedirection and if on the outside, in the other direction, and it isscored accordingly.

The sealing seam is wider than the folded-over skived strip by enough toobtain a bond beyond this strip. This part of the sealing seam may .beas wide as or somewhat wider than the folded strip. The sealing may beaccomplished by the application of heat and pressure to the matingportions of the folded blank. The top and bottom portions of thecontainer are formed on their scored lines and suitably sealed.

BRIEF DESCRIPTION OF DRAWING The features of this invention will beunderstood more fully and clearly from the ensuing description ofillustrative embodiments thereof taken in connection with the appendeddrawings in which:

FIG. 1 shows a container blank on which the location of the scored linesand of the skived portion are indicated;

FIG. 2 is a perspective view of the erected container;

FIG. v3 is a section of the blank showing the location of skived andscored portions;

FIG. 4 is a section similar to FIG. 3 but with half of the skivedportion folded unto the other half;

FIG. 5 is a section on line 55 of FIG. 2 showing a side seam assembledwith the sealing or fifth panel inside the adjoining-body panel; and

FIG. 6 is a section similar to that of FIG. 5 but with the sealing paneloutside of the adjoining body panel.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS As seen in FIG. 1, the blank 10comprises the four body panels 11, 12, 13 and 14, and the side seampanel 15. The panel 15 has a strip skived over a portion of its width asindicated by 16 as is more fully shown in FIG. 3. The sidewall portionsof the blank are denoted as 11w, 12w, 13w and 14w. The portions of thetop and bottom or end of the container are denoted as III, 12!, Br and14! and 112, 12c, 13c and 14e, respectively. The location of some of thenecessary scored lines is indicated by dotted lines l8, 19, 20 and 21.

FIG. 2 shows the assembled container in perspective. The side-seam panelis on the inside and its edge is indicated by the dotted lines. Thereference characters correspond to those of FIG. 1.

The sectional view of a portion of the container blank shown in FIG. 3indicates where the side seam panel 15 has been reduced up to theshoulder 15a by skiving. The skiving removes material down toessentially half the thickness of the blank leaving a half-thicknessportion 16. A line 17 is scored down the middle of the skived strip onits coated side and parallel to the scored line 18 at the intersectionof the panels 14 and 15.

In the view of FIG. 4, the skived strip 16 is bent on the scored line 17so that the skived faces are in contact. The edge of the strip 16 fitssnugly against the shoulder 15a of the full thickness portion of thefifth panel 15. Because of the scored line 17 and a good fit, noadhesive is required in this fold. However, the fold line 17 should beironed, as by passing the blank between a pair of rollers after the foldhas been made, as shown in FIG. 4, to reduce the tendency for the end ofpanel 16 to spring back. Such ironing keeps the fold from unfoldingduring the heat-activation period.

A corner joint between the sidesealing panel 15 and the sidewall panel11 is shown in FIG. 5. The sidewall or body panel 14 is shown as bent onthe scored line 18. This represents a corner with the fifth panel 15inside of the container.

In FIG. 5, the laminae of the coated paperboard are denoted. The plasticcoatings Ila and are on opposite faces of the paperboard 11b. This ofcourse applies to the whole blank and not only to what is disclosed ofpanel 11.

In FIG. 6, the fifth panel 15 is represented as outside of the firstpanel 11. In order that this may be done a scored line 18a may be madeon the side of the blank 10 opposite to the line 18 as it is shown inFIGS. 3 and 4.

The joint is bonded by the application of heat and pressure thereto byconventional means for sealing containers of this kind. It will be notedin the joints of both FIGS. 5 and 6 that the folded-over portion 16 ofthe panel 15 is between 15 and the panel 11 to which it is sealed. Itwill be further noted that the bonding includes a portion of the panel15 that has not been skived and is therefore of the full thickness ofthe blank. In FIG. 6 the edge of the panel 11 butts tightly against theside of the panel 14. Thus a strong leakproof joint is afforded.

The foregoing is a description of illustrative embodiments of theinvention and is not intended as a limitation on what is claimed.

What is claimed is:

l. A fluid-packaging container which is resistant to penetration by thecontained fluid and which protects the fluid from unwanted externalsubstances, the container being constructed from a blank of foldable,plastic coated sheet material divided by scored lines into a pluralityof contiguous sidewall 5 panels and a side seam panel, each paneldivided by other scored lines into top, body and bottom and having onesurface of the side-seam panel bonded to the free margin of a sidewallpanel,

the side seam panel having a full thickness strip extending from andintegral with the edge of one of said sidewall panels and a skived edgestrip extending from and integral with the edge of said full thicknessstrip, said skived edge strip being skived substantially uniformly fromone surface to a thickness of substantially one-half the thickness ofsaid plastic coated sheet material, said skived edge strip having acentrally located scored line and being folded about said scored linewith the skived surfaces being in intimate contact with each other, thefree edge of said skived edge strip abutting against the free edge ofsaid full thickness strip,

the outer surface of the folded portion of the skived strip being partof the surface bonded to the adjacent sidewall,

and

top and bottom closure portions defined respectively by the top and thebottom sections of the panels.

2. A container as in claim 1 in which the plastic layers comprise alow-density polyethylene.

3. A container as in claim l-in which there are four sidewall panelsdefining a container rectangular in section.

4. A blank for a container for packaging fluids which tend to penetratethe container or are contaminated by the ingress of foreign materials,which comprises a foldable sheet of paperboard having both faces coatedwith an essentially impervious plastic layer, the sheet being divided byscored lines into a plurality of sidewall panels and a side seam panel,the side seam panel including a skived strip adjacent to one edge and ascored folding line parallel to its edge in the center of the skivedstrip on its unskived face, the remaining thickness of said skived stripbeing uniformly substantially one-half the thickness of said sheet, thefree edge of the unskived portion of said side seam panel forming ashoulder against which the free edge of said skived strip is adapted toabut when said skived strip is folded about said scored folding linewith the skived surfaces in intimate contact with each other.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION patent 3,604 ,613Dated September 14, 197].

Inventor(s) Haas et a1.

It is certified that error appears in the shove-identified patent andthat said Letters Patent are hereby corrected as shown below:

Col. 1, line 29, "for" should be --from--.

Col. 3, line 7, after "bottom" insert --sections, which comprises a bodyportion defined by the side wall panels-.

Signed and sealed this 7th day of March 1972.

(SEAL) Attest:

ROBERT GOTTSCHALK EDWARD M.FLETCHEB,JR.

Commissioner of Patents Attesting Officer-

1. A fluid-packaging container which is resistant to penetration by thecontained fluid and which protects the fluid from unwanted externalsubstances, the container being constructed from a blank of foldable,plastic coated sheet material divided by scored lines into a pluralityof contiguous sidewall panels and a side seam panel, each panel dividedby other scored lines into top, body and bottom and having one surfaceof the side-seam panel bonded to the free margin of a sidewall panel,the side seam panel having a full thickness strip extending from andintegral with the edge of one of said sidewall panels and a skived edgestrip extending from and integral with the edge of said full thicknessstrip, said skived edge strip being skived substantially uniformly fromone surface to a thickness of substantially one-half the thickness ofsaid plastic coated sheet material, said skived edge strip having acentrally located scored line and being folded about said scored linewith the skived surfaces being in intimate contact with each other, thefree edge of said skived edge strip abutting against the free edge ofsaid full thickness strip, the outer surface of the folded portion ofthe skived strip being part of the surface bonded to the adjacentsidewall, and top and bottom closure portions defined respectively bythe top and the bottom sections of the panels.
 2. A container as inclaim 1 in which the plastic layers comprise a low-density polyethylene.3. A container as in claim 1 in which there are four sidewall panelsdefining a container rectangular in section.
 4. A blank for a containerfor packaging fluids which tend to penetrate the container or arecontaminated by the ingress of foreign materials, which comprises afoldable sheet of paperboard having both faces coated with anessentially impervious plastic layer, the sheet being divided by scoredlines into a plurality of sidewall panels and a side seam panel, theside seam panel including a skived strip adjacent to one edge and ascored folding line parallel to its edge in the center of the skivedstrip on its unskived face, the remaining thickness of said skived stripbeing uniformly substantially one-half the thickness of said sheet, thefree edge of the unskived portion of said side seam panel forming ashoulder against which the free edge of said skived strip is adapted toabut when said skived strip is folded about said scored folding linewith the skived surfaces in intimate contact with each other.